During the cold winter months, warm-weather plants, such as the tropical hibiscus (Hibiscus rosa-sinensis), require protection from frost. Hibiscus plants grow in U.S. Department of Agriculture plant hardiness zones 9 through 10, and are known for their glossy foliage and brightly colored flowers. There are reports of hibiscus plants reaching 15 feet in height, however, most only grow to a height of 5 to 6 feet. Once temperatures drop to 20 degrees Fahrenheit, you'll need to cover the hibiscus plants with a frost cloth.
1 Distribute a 3-inch-deep layer of leaf mulch around the base of your tropical hibiscus plants. The mulch should be wide enough to cover the entire root area. This helps keep the ground warm during the frost.
2 Select a frost cloth based on the predicted temperature. Some frost cloths only provide an extra 4 degrees of warmth, while others provide 8 degrees.
3 Lay the frost cloth directly over the hibiscus plants. It is okay if the cloth touches or lays on top of the plant. The cloth must reach the ground on all sides.
4 Set weights on the bottom of the frost cloth to secure it to the ground.
Items you will need
- Frost cloth
- Water your hibiscus plants the morning before a frost is set to occur. This will keep the soil moist so that it retains the heat.
- Compost can be used in place of the leaf mulch.
- Never use a regular plastic or cloth cover on your hibiscus plants without constructing a framework of stakes to hold it off the plant. The cover will stick to the hibiscus during a freeze, instead of offering it the protection it requires.
- Texas A&M AgriLife Extension: Tropical Hibiscus ( Hibiscus Rosa-sinensis)
- Hidden Valley Hibiscus: Wintering Tropical Hibiscus
- University of California Sacramento Master Gardeners: Frost Protection for Sensitive Plants
- University of Florida IFAS Extension: The Right and Wrong Ways to Protect Plants From Cold
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